Field of the Invention
The present invention relates to a communication apparatus which transmits or receives an image that is read from an original document, a method of controlling the same and a computer-readable storage medium.
Description of the Related Art
There exists S/MIME (Secure/Multipurpose Internet Mail Extensions) defined by RFC 2311 as a technique for enhancing security of an electronic mail, and this enables realization of encryption of electronic mail data. An Internet facsimile apparatus (IFAX) that performs communication of an image that is read in by a scanner and attached to an electronic mail also is widely used. In Japanese Patent Laid-Open No. 2004-297767 there is proposed an apparatus that comprises an electronic mail transmission mode and an IFAX mode. Also, in Japanese Patent Laid-Open No. 2007-26173 there is proposed a technique for adding a signature of multiple people in charge of one document as a technique which uses a digital signature. In Japanese Patent Laid-Open No. 2005-159726 there is proposed a technique for transmitting a certificate description item of an instructor of transmission as transmission source information when user authentication succeeds.
However, there is a problem with the above described conventional technique as is described below. For example, in an electronic mail mode, transmission using various file formats such as PDF, or the like, can be performed, and adding a signature is also possible, making it possible to identify who performed the transmission, and from what machine they performed the transmission. However, because the IFAX mode is limited to TIFF files, a signature, or the like, cannot be added. Therefore, there exists a problem in that in the case that a From address is falsified by a person with malicious intent, tracking is difficult, and the ability to suppress information leakage does not work. Also, there exists a problem in that in an IFAX mode, generally, mail data does not remain after transmitting an electronic mail using S/MIME, and since mail data is deleted if an attached file is printed, it is difficult for a user to confirm a digital signature.